meta-stx: set preempt-rt as the default kernel

- Set preempt-rt as the default kernel
- Add rt-tests into the image
- Remove extra boot menus since only the AIO controller with
  preempt-rt kernel will be built and supported.

Issue-ID: INF-121
Signed-off-by: Jackie Huang <jackie.huang@windriver.com>
Change-Id: I3afaeb510607e5bbb5cf3adb97480f04abcd03d0
diff --git a/meta-stx/conf/distro/files/syslinux.cfg b/meta-stx/conf/distro/files/syslinux.cfg
index cc23c56..175e762 100644
--- a/meta-stx/conf/distro/files/syslinux.cfg
+++ b/meta-stx/conf/distro/files/syslinux.cfg
@@ -26,59 +26,14 @@
 # ----------------------------------------
 
 
-# Standard Controller menu
-menu begin
-  menu title Standard Controller Configuration
+# AIO Controller - Serial Console menu
+label 2
+  menu label All-in-one Controller Configuration - Serial Console
+  kernel /bzImage
+  append initrd=/initrd rootwait console=ttyS0,115200 inst.text serial inst.stage2=hd:LABEL=oe_iso_boot boot_device=sda rootfs_device=sda biosdevname=0 usbcore.autosuspend=-1 inst.gpt security_profile=standard user_namespace.enable=1 ks=/installer-config/ks.cfg
 
-  # Serial Console submenu
-  label 0
-    menu label Serial Console
-    menu disable
-    kernel /bzImage
-    append initrd=/initrd rootwait console=ttyS0,115200 inst.text serial inst.stage2=hd:LABEL=oe_iso_boot boot_device=sda rootfs_device=sda biosdevname=0 usbcore.autosuspend=-1 inst.gpt security_profile=standard user_namespace.enable=1 ks=/installer-config/controller_ks.cfg
-  
-  # Graphical Console submenu
-  label 1
-    menu label Graphical Console
-    menu disable
-    kernel /bzImage
-    append initrd=/initrd rootwait console=tty0 inst.text inst.stage2=hd:LABEL=oe_iso_boot boot_device=sda rootfs_device=sda biosdevname=0 usbcore.autosuspend=-1 inst.gpt security_profile=standard user_namespace.enable=1 ks=/installer-config/controller_ks.cfg
-menu end
-
-menu SEPARATOR
-
-# AIO Controller menu
-menu begin
-  menu title All-in-one Controller Configuration
-
-  # Serial Console submenu
-  label 2
-    menu label Serial Console
-    kernel /bzImage
-    append initrd=/initrd rootwait console=ttyS0,115200 inst.text serial inst.stage2=hd:LABEL=oe_iso_boot boot_device=sda rootfs_device=sda biosdevname=0 usbcore.autosuspend=-1 inst.gpt security_profile=standard user_namespace.enable=1 ks=/installer-config/ks.cfg
-  
-  # Graphical Console submenu
-  label 3
-    menu label Graphical Console
-    kernel /bzImage
-    append initrd=/initrd rootwait console=tty0 inst.text inst.stage2=hd:LABEL=oe_iso_boot boot_device=sda rootfs_device=sda biosdevname=0 usbcore.autosuspend=-1 inst.gpt security_profile=standard user_namespace.enable=1 ks=/installer-config/ks.cfg
-menu end
-
-menu SEPARATOR
-
-# AIO (Low Latency) Controller menu
-menu begin
-  menu title All-in-one (lowlatency) Controller Configuration
-
-  # Serial Console submenu
-  label 4
-    menu label Serial Console
-    kernel /bzImage
-    append nitrd=/initrd rootwait console=ttyS0,115200 inst.text serial inst.stage2=hd:LABEL=oe_iso_boot boot_device=sda rootfs_device=sda biosdevname=0 usbcore.autosuspend=-1 inst.gpt security_profile=standard user_namespace.enable=1 ks=/installer-config/aio_lowlatency_ks.cfg
-
-  # Graphical Console submenu
-  label 5
-    menu label Graphical Console
-    kernel /bzImage
-    append initrd=/initrd rootwait console=tty0 inst.text inst.stage2=hd:LABEL=oe_iso_boot boot_device=sda rootfs_device=sda biosdevname=0 usbcore.autosuspend=-1 inst.gpt security_profile=standard user_namespace.enable=1 ks=/installer-config/aio_lowlatency_ks.cfg
-menu end
+# AIO Controller - Graphical Console menu
+label 3
+  menu label All-in-one Controller Configuration - Graphical Console
+  kernel /bzImage
+  append initrd=/initrd rootwait console=tty0 inst.text inst.stage2=hd:LABEL=oe_iso_boot boot_device=sda rootfs_device=sda biosdevname=0 usbcore.autosuspend=-1 inst.gpt security_profile=standard user_namespace.enable=1 ks=/installer-config/ks.cfg